Socket extension adapter



NOV. 13, 1934. w, Dl KYLE ET AL. 1,980,488

SOCKET EXTENS I ON ADAPTER Filed Feb. 14, 1930 Patented Nov. 13, 1934 UNITED STATESv PATENT oFFicE SOCKET rEXTEN SION ADAPTER Delaware Application February 14, 1930, Serial No. 428,353

4 Claims.

This invention relates to socket extensions for electric lamps.

For a great length of time the relatively large electric lamps, such as those of the series type used for street lighting, were made with a standard distance to the light center, and reflectors and fixtures were designed for this standard light center dimension and were extensively sold and installed. Recently, however, the lamp inanufacturers have redesigned their lamps with a different dimension or distance to the light center considerably less than that for which the reiiectors and fixtures were designed.

When these new lamps are usedwith the old, installed iixtures, the light center is entirely too high up in the fixture to give proper distribution of light. Obviously, discarding and replacing the vast number of installed xtures would result in a prohibitive expense.

This invention is designed to overcome the defects noted above, and objects of this invention are to provide a socket extension which may be inserted in the old socket and which will receive a lamp of the new style and properly position the light center so that the correct distribution of light is obtained.

Further objects of this invention are to provide a socket extension which may be used in a series system in which short circuiting switches are carried by the sockets, in which means are provided in the socket extension which will not disturb the short circuiting switch when the socket extension is inserted in the old style of socket, but which will open the short circuiting switch when a lamp is inserted in the socket extension.

Further objects are to provide a socket extension which may be used by unskilled laborers with the assurance that no damage can be done whether the socket extension is provided with a lamp or not, at the time such socket extension is inserted in the old socket, and which will withstand rough handling as it is devoid of fragile or easily broken parts.

Further objects are to provide a socket extension which is of simple construction, which may be made by quantity production methods, and which is cheap to produce.

An embodiment of the invention is shown in the accompanying drawing, in which:

Figure 1 is a sectional view through the socket extension showing it in place in an old type of socket, such view corresponding to a section on the line 1-1 of Figure 2.

Figure 2 is a bottom View of the device.

Figure 3 is a fragmentary sectional view through the socket, such views being taken at right angles to Figure 1.

Referring to the drawing, it will be seen that the adapter comprises a body portion, formed of porcelain or other insulating material, which has a reduced projecting portion 1 provided with an externally threaded part, which may be formed by means of the threaded ferrule 2 having the inturned upper flange 3. This body portion is provided with an enlarged part 4, which is recessed and provided with internal threads. These internal threads may be furnished by means of a threaded ferrule 5 of metal, which has an in-v turned annular flange at its upper end. The portion 4 is provided with internally arranged slots 7, y

within which the outwardly projecting feet of friction clips or spring clips 8 are adapted to be positioned, such spring clips projecting` through slots formed in the ferrule 5 to provide frictional portions for engaging the base of a lamp in the usual manner. The inwardly turned flanges 3 and 6 of the two threaded metal ferrules are electrically joined in any suitable manner, as by means of the screws or, bolts 9, which extend through the porcelain, and which may be threaded at their outer ends into a washer or clamping member 10, which is drawn inwardly against the flange 3. The screws 9 thus not only electrically connect the two ferrules, but also hold them in place.

It is preferable to provide an outwardly projecting cylindrical portion or neck 11 at the upper end of the device and a similar projecting neck 12 at the lower end, such latter neck projecting into the lower lamp base receiving recess.

The adapter is provided with an axially arranged movable plunger 13 formed of metal and provided with a lower head or flange 14 and an upper head or flange 15. This plunger is loose and is free to be moved upwardly by means of the base of the inserted lamp.

The adapter is so constructed that it may be screwed into any of the usual types of sockets, such, for example, as the socket 16 used in the series lighting system. This socket is regularly provided with a threaded ferrule 1'7 and a center contact 18 connected to a short circuiting switch 19, see Figure 3. The short circuiting switch is urged towards closed position by means of the small spring 20, and is connected to one of into the conventional socket 16, the center contact of the lamp lifts the shortcircuiting switch and the current passes through the lamp.

However, when the lamps having a shorter dimension from their light centers to their bases as previously described are employed, their light centers do not Acome in the proper position for the standard reectors and ttings.

The adapter disclosed in this invention is adapted to be screwed into the lamp socket and to correctly position the light center of the new types of shortened lamps. However, when the adapter is screwed into place, the short circuiting switch is still freely and satisfactorily operated as heretofore by means of the inserted lamp. For example, when a lamp is screwed into the socket of the adapter when the parts are in the position of Figure 1, it is obvious that the center contact of the lamp base will engage the head 14 of the plunger 13 and force the plunger upwardly. The head 15 of theplunger contacts with the center contact 18, see Figure 3, of the conventional socket 16 and opens the short circuiting switch 19.A

However, when the lamp is removed, the short circuiting switch again closes and the plunger 13 moves downwardly.

It is apparent also from a consideration of Figure l that the short circuiting switch is not open when the adapter is screwed into place without a lamp. f The shouldered portions 22 of theadapter contact with the base of the socket 16 and limit the upward motion of suchadapter, thus preventing opening of the short circuiting switch.

It will be seen that a very simple, rugged, easily constructed, and cheap adapter has been provided by this invention.

lItwill-be seen further that the device may be handled by unskilled labor without any thought on the part of the operator and with assurance that it will satisfactorily cooperate with any of th standard Vtypes of sockets. 1

Although this invention has been described in considerable detail, it is to be understood that such description is intendedas illustrative rather thanlimiting, -as the invention may be variously embodied and is to be interpreted as claimed.

We claim:

1. The combination of a socket having an internally threaded metal ferrule and having a central, movable, electrical contact and a short circuiting switch operated by said central, movable contact; and an adapter for insertion within said socket, saidy adapter having its lower portion provided with an. internally threaded metal ferrule and having its upper portion provided with an external threaded metal ferrule'screwed into the internally threaded metal ferrule of said socket and electrically connected to the lower ferrule of said adapter, said adapter having a. centrally located metal rod 'movably contacting with said movable central contact of said socket, said rod being axially movable within said adapter and being electrically insulated from both ferrules of said adapter.

2. The combination of a socket having an internally threaded metal ferrule and having a central, movable, electrical contact and a short circuiting switch operated by said central, movable contact; and an adapter comprising avbody portion of insulating material provided with a. socket at one end and a reduced portion projecting from the other end, a threaded metal ferrule surrounding the projecting portion and screwed into the internally threaded metal ferrule of said socket; a threaded metal ferrule carried within said adapter, means electrically connecting the `ferrules of said adapter, and an axially arranged metal rodV movably contacting with said movable central contact of said socket, said rod being axially movable within said adapter and being electricallyinsulated from bothy ferrules of said adapter.

3. The combination of a socket having an internally threaded metal ferrule and having a central, movable, electrical contact and a short circuiting switch operated by said central, movable contact; and an adaptercomprising a body portion of insulating material provided witha socket at one end and a reduced portion projecting from the other` end, a threaded metal ferrule surrounding'the projecting portion and screwed into the internally threaded metal ferrule of said socket; a threaded metal ferrule carried within said adapter, means electrically connectingA the ferrules of said adapter and mechanically holding said ferrules inV place, and an axially arranged metal rod movably contacting with said movable central contact of said socket, said rod being axially movable within said adapter and being electrically insulated from both ferrules of said adapter. ,4. In a devicel of the character described, an electrical socket member having a iixed contact, a movable contact, and a short-circuiting lswitch operable by the movable contact and normally closed, in combination with an adapter `having a portion receivable in the electrical socket member and having a socket, a metalferrule within the socket of said adaptenmeans electrically connecting the ferrule with the. xed contact on said member, and movable contactgmeans extending through the adapter for contact with the movable contact on said socket and for actuation thereof to open said switch.

WILLIAM D. KYLE. 1 ALWIN G. S'IEINMAYERj` 

